Explosion circuit breaker

ABSTRACT

An explosion type circuit breaker incorporating a hollow current-carrying bus containing an explosive charge and detonator characterized in that the current-carrying bus is provided with dielectric sheathings covering outer and inner surfaces of the hollow current-carrying bus, the dielectric sheathing covering the inner surface of the current-carrying bus having an annular groove and the explosive charge having an annular cumulative recess lined with a dielectric and facing the above-mentioned annular groove of the dielectric sheathing.

United States Patent [191 Kozorezov et al EXPLOSION CIRCUIT BREAKER [76]Inventors: Konstantin lsaakovich Kozorezov, Universitetsky prospekt, 21,korp. l, kv. 29; Vitaly Vasilievich Semchenko, ulitsa 26 BakinskikhKomissarov, 8, korp. 3, kv. 32; Viktor Vasilievich Biteryakov, ulitsaVvedenskogo, 7, kv. 98; Georgy Ivanovich Mikhailu, ulitsa Volgina, 23,korpus l, kv. 52; Nine! Fedorovna Skugorova, ulitsa BolshayaCheremushkinskaya, 57, korp. 30, kv. 23, all of Moscow, U.S.S.R.

[22] Filed: May 18, 1972 [211 Appl. No.: 254,679

[ June 25, 1974 [58] Field of Search ZOO/61.08

[56] References Cited UNITED STATES PATENTS 3,1 l7 l94 1/1964 Stresau.Jr. ZOO/61.08

Primary ExaminerJames R. Scott Attorney, Agent, or FirmHolman & Stern [57] ABSTRACT An explosion type circuit breaker incorporating a hollowcurrent-carrying bus containing an explosive charge and detonatorcharacterized in that the current-carrying bus is provided withdielectric sheathings covering outer and inner surfaces of the hollowcurrent-carrying bus, the dielectric sheathing covering the innersurface of the current-carrying bus having an annular groove and theexplosive charge having an annular cumulative recess lined with adielectric and facing the above-mentioned annular groove of thedielectric sheathing.

3 Claims, 5 Drawing Figures fis s w I V/oxwW PATENTEDJUN 25 m4 7 3,819890 SHEU 2 [1F 3 A'\ A V//// F/ZJ. J

W Wm

PATENTEDJUHZSIW 3,819,890

sum 3 0F 3 V/// //////////g W EXPLOSION CIRCUIT BREAKER BACKGROUND OFTHE INVENTION 1. Field of the Invention This invention relates to thefield of electrical engineering and more particularly to explosioncircuit breakers which provide a means for quick circuit interruptionand breaking of heavy-current and high-voltage circuits.

2. Description of Prior Art In view of the general trend in present-dayscience and engineering technology to raise the unit capacity ofelectric power and electrophysical installations such as generator sets,capacitive and inductive energy accumulators, installations forthermonuclear fusion, etc the problem of protection of these largeinstallations arises during emergency conditions, also, switching ofhighpower and extra-high-power circuits is being given greatconsideration.

Certain difficulties have to be overcome in solving the above problemsas they call for rapid interruption of high-voltage and heavy-currentcircuits.

Solution of these problems by conventional methods has led to thedevelopment of circuit breakers with various types of arc quenchingmeans (air-blast, magnetic blast), and insulating fillings such as in,for example, oil-filled circuit breakers. These circuit breakers relyfor their operation on mechanical interruption of the electric circuitand extinction of the are between the separating contacts by cooling andlengthening the arc gap. However, the operating time of these circuitbreakers amounts to several milliseconds since the arc is lengthened ata rate of about a few tens of metres per second.

Known in the present state of the art are circuit breakers whereincharges of explosives are used to increase the speed of interruption ofthe electric circuit. Such circuit breakers comprise a hollow currentcarrying conductor, preferably of tubular shape, containing an explosivecharge and a detonator. The hollow conductor has longitudinal slits andtransverse notches and seams within the narrowed middle or end part ofthe conductor. On explosion of the charge, the conductor bursts andspreads out into a kind of rosetter. while the hollow ends of theconductor serve as nozzles for extinguishing the breaking current are byjets of the products of explosion.

In practice, however, the operating time of this device cannot be madeshorter than 30 to 40 microseconds. This is due mainly to the twofollowing factors: firstly the speed of interruption of the electriccircuit does not exceed l to 2 mm per microsecond (increase of the speedup to 3 mm per microsecond calls for a considerable increase of theexplosive charge), secondly the arc is quenched by explosion productswhich are of relatively low dielectric strength (the products of theexplosion expand and their pressure drops with the sixth power of theradius of space occupied by these products).

SUMMARY OF THE INVENTION A primary object of the present invention is toeliminate the above-mentioned disadvantages.

It is a further object of the present invention to provide an explosioncircuit breaker having an operating time of l to 5 microsecondsemploying a limited explosive charge.

These objects are accomplished by the present circuit breakerincorporating a hollow current-carrying bus containing an explosivecharge and detonator; in accordance with the disclosed invention, thehollow current-carrying bus is provided with dielectric sheathings onits inner and outer surfaces and the dielectric sheathing on the innersurface of the currentcarrying bus has an annular groove and theexplosive charge has an annular cumulative recess lined with adielectric and facing the above-mentioned annular groove of thedielectric sheathing.

A second version of the present invention consists in that thedielectric sheathing covering the outer surface of the above-mentionedcurrent-carrying bus has an annular groove formed opposite the annulargroove of the dielectric sheathing which covers the inner surface of theabove-mentioned current-carrying bus.

BRIEF DESCRIPTION OF THE DRAWING The above and other objects, advantagesand features of the present invention will be more fully understood fromthe following detailed description of its embodiments considered inconnection with the accompanying drawings, in which:

FIG. 1 illustrates a cross-sectional view of an explosion type circuitbreaker constructed in accordance with the present invention, thisFigure showing the position of the circuit breaker components before theexplosion;

FIG. 2 is a cross-sectional view of the embodiment 0 FIG. 1 showing theposition of the circuit breaker components during the explosion;

FIG. 3 is a cross-sectional view of another embodiment of theexplosion-type circuit breaker in accordance with the teachings of thepresent invention, this Figure depicting the position of the circuitbreaker components before the explosion;

FIG. 4 is a cross-sectional view of the embodiment of the invention ofFIG. 3, depicting the position of the circuit breaker components duringthe explosion; and

FIG. 5 is a cross-sectional view of the embodiment of the inventiondepicted in FIG. 1, this Figure illustrating the condition of thecurrent bus following the explosion.

DESCRIPTION OF PREFERRED INVENTIVE EMBODIMENTS The explosion circuitbreaker incorporates tips 1 (FIG. 1) in which the hollowcurrent-carrying bus 2 of cylindrical shape is fixed. The outer surfaceof the current-carrying bus 2 is covered by a dielectric sheathing 3made as a hollow cylinder. The inner surface of the current-carrying bus2 is covered by an inner dielectric sheathing 4 made as a hollowcylinder. The sheathing 4 has an annular groove 5.

An explosive charge 6 and detonator 7 are arranged inside the hollowcurrent-carrying bus 2. The explosive charge 6 is in the form of a discthe side surface of which has an annular convergent or concave recesslined with a dielectric 9. As will be appreciated by those skilled inthis art, the assembly constituting members 6 through 9 can be mountedin any convenient and known manner within the current-carrying bus 2having sheathing 3 through 4. One technique by which such mounting canbe effected is by means of plugs having annular centering grooves intheir ends, one of the plugs having a through center hole for the wiresof the detonator 7. Such plugs are widely known in this field andconstitute prior art. In that such plugs are not important for anunderstanding of the principles taught by the instant invention, nospecific illustration of same has been shown.

The explosive charge 6 is positioned so that the annular recess 8 isopposite the annular groove of the inner dielectric sheathing 4.

The explosion circuit breaker operates in the following manner, andattention is directed to FIG. 2.

On receiving an external control signal, the detonator 7 and theexplosive charge 6 operate in succession. After detonation of theexplosive charge 6, the material of the lining 9 forms itself into ahigh-speed cumulative jet [0 and pestle 11. Both the cumulative je t l0and the pestle 11 are in the form of discs moving radially with a speedof and 10 m per second, respectively. The thickness of the cumulativejet 10 depends on the shape of the recess 8, the thickness and densityof the lining 9, the speed of detonation within the explosive charge 6and is from 0.1 to 0.9 of the width of the cumulative recess.

In order to avoid energy losses of the dielectric cumulative jet I0needed to rupture the inner dielectric sheathing 4, this sheathing isprovided with the abovementioned annular groove 5.

After passing into the annular groove 5, the cumulative jet l0 strikesthe current-carrying bus 2. As a result. the jet 10 turns around andforms a film 12. The current-carrying bus 2 splits by bursting onexplosion and its parts are accelerated in the direction perpendicularto the direction of motion of the cumulative jet l0. Afterwards, thecumulative jet 10 goes farther into the body of the outer dielectricsheathing 3.

The shattering of the current carrying bus 2 occurs in the course of lto 5 microseconds since the speed of penetration of the jet amounts toabout 5 mm per second.

The pressure developed at the point of contact of the dielectriccumulative jet I0 and the outer dielectric sheathing 3 attains hundredsof atmospheres and so the arc of the breaking current is intensivelycooled and quenched.

Thus, the dielectric sheathing 3 sets up head for the cumulative jet l0and contributes to the development of high pressure within the region ofthe interaction. Furthermore, the outer dielectric sheathing preventsbreakdown along the surface of the destroyed currentcarrying bus 2.Electric breakdown along the inner surface of the current-carrying bus 2is prevented by the inner dielectric sheathing 4 and the products ofexplosion of the explosive charge 6 which expand in the axial direction.The body of the dielectric cumulative jet 10, the film l2 and the pestleI] prevent breakdown between the ends of the destroyed current-carryingbus 2. Reference is made to FIG. 5 for an illustration of the bus afterthe explosion.

The construction of the explosion circuit breaker shown in FIG. 3differs from that shown in FIG. 1 in that the dielectric sheathing 3covering the outer surface of the current-carrying bus 2 is alsoprovided with an annular groove 13 (FIG. 3).

The explosion circuit breaker shown in FIG. 3 oper ates in the same wayas the explosion circuit breaker shown in FIG. 1, the only differencebeing that the section of the current-carrying bus 2 located between thegrooves 5 and 13 is sheared off and moves radially outward at a highspeed radially away from the break. Reference is made to FIG. 4 in thisrespect.

The explosion circuit breaker described above may be used without thedielectric lining 9 of the recess 8 of the explosive charge 6. It shouldbe noted, however, that employment of the above-mentioned dielectriclining greatly improves the efficiency of operation of the explosioncircuit breaker.

Thus, the present invention allows the shortening of the operating timeof the explosion circuit breaker down to a value of l to 5 microseconds,recudes the weight of the explosive charge and improves its dielectricstrength.

What is claimed is:

1. An explosive type electric power circuit breaker comprising:

a hollow current-carrying tubular bus;

outer and inner dielectric sheathings disposed respectively on the outerand innersurfaces of said hollow current-carrying tubular bus;

an annular groove formed on the periphery of said inner dielectricsheathing;

an explosive charge disposed inside said hollow current-carrying tubularbus, said explosive charge being shaped so as to have an annular notchshaped recess positioned opposite said annular groove in said innerdielectric sheathing; and

a detonator means for igniting and exploding said explosive charge at amoment when the electric power circuit in said hollow current-carryingtubular bus is desired to be interrupted;

said recess of said explosive charge directing the explosive forcetowards said annular groove of said tubular bus such that said busbursts along a circumferential region adjacent of said annular groove soas to cause swift interruption of the electric power circuit.

2. An explosive circuit breaker as claimed in claim 1, wherein saidouter dielectric sheathing disposed along the outer suface of saidhollow current-carrying tubular bus is provided with an annular groovepositioned opposite the annular groove made in the said inner dielectricsheathing so as to facilitate a more effective interruption of theelectric circuit.

3. An explosive circuit breaker as claimed in claim 1, wherein saidannular notch-shaped recess is lined with a dielectric substance,whereby said dielectric lining serves to impinge violently against saidcurrentcarrying tubular bus so as to facilitate a more effectiverepturing thereof,- when a circuit interruption is initiated bydetonating said explosive charge.

1. An explosive type electric power circuit breaker comprising: a hollowcurrent-carrying tubular bus; outeR and inner dielectric sheathingsdisposed respectively on the outer and inner surfaces of said hollowcurrent-carrying tubular bus; an annular groove formed on the peripheryof said inner dielectric sheathing; an explosive charge disposed insidesaid hollow current-carrying tubular bus, said explosive charge beingshaped so as to have an annular notch-shaped recess positioned oppositesaid annular groove in said inner dielectric sheathing; and a detonatormeans for igniting and exploding said explosive charge at a moment whenthe electric power circuit in said hollow current-carrying tubular busis desired to be interrupted; said recess of said explosive chargedirecting the explosive force towards said annular groove of saidtubular bus such that said bus bursts along a circumferential regionadjacent of said annular groove so as to cause swift interruption of theelectric power circuit.
 2. An explosive circuit breaker as claimed inclaim 1, wherein said outer dielectric sheathing disposed along theouter suface of said hollow current-carrying tubular bus is providedwith an annular groove positioned opposite the annular groove made inthe said inner dielectric sheathing so as to facilitate a more effectiveinterruption of the electric circuit.
 3. An explosive circuit breaker asclaimed in claim 1, wherein said annular notch-shaped recess is linedwith a dielectric substance, whereby said dielectric lining serves toimpinge violently against said current-carrying tubular bus so as tofacilitate a more effective repturing thereof, when a circuitinterruption is initiated by detonating said explosive charge.